Patrick Hetzner tried diets and exercise, just about everything short of stomach stapling to lose weight. Nothing worked. Five months ago he tried something new: a stomach pacemaker that curbed his appetite.

Since having it implanted, Hetzner, a 20-year-old Munich mailman, has knocked off more than 10 kilos (22 pounds) from his earlier weight of 104 kilos (229 pounds).

Hetzner got the device as part of a clinical trial. Since being approved by Britain last month, the device is available for sale across the European Union. It works a bit like a cardiac pacemaker, and consists of a stimulator and a sensor surgically implanted onto the stomach.